The testing times for a group of college students were normally distributed with a mean of u = 31 minutes and a standard deviation of o = 4.8 minutes. The bell curve below represents the distribution for testing times. The scale on the horizontal axis is equal to the standard deviation. Fill in the indicated boxes. µ = 31 o = 4.8 H-30 u-20 u-o μ+20 μ+3σ Used the Empirical Rule to complete the following statements: 68% of testing times were between minutes and minutes. 95% of testing times were between minutes and minutes. 99.7% of testing times were between minutes and minutes. 50% of testing times were below minutes.

You are given that X follows a Weibull distribution where alpha = 2.3 beta = 17.4 What is the value of the the 60th percentile of this distribution?

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The time to complete an exam is approximately Normal with a mean μ = 47 minutes and a standard deviation o = 8 minutes. The bell curve below represents the distribution for testing times. The scale on the horizontal axis is equal to the standard deviation. 1. Fill in the indicated boxes. μ-3σ μ-2ο μίσ + μ μ+o 47 minutes. 2. Used the Empirical Rule to complete the following statements: 95% of testing times were between and μ = 47 σ = 8 μ+20 μ+30 minutes and 55 minutes. minutes % of the testing times were between 39

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 7.5 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 66 samples is 7.7 ppm with a standard deviation of 1.0 Does the data support the claim at the 0.025 level? Assume the population distribution is approximately normal. Step 2 of 5 :   Find the value of the test statistic. Round your answer to three decimal places. Specify if the test is one-tailed or two-tailed. Determine the decision rule for rejecting the null hypothesis. Round your answer to three decimal places. Make the decision to reject or fail to reject the null hypothesis.

If you chose the α level of .01, then which of the following p value will allow you to conclude that your result is statistically significant?   a. 0.005   b. 0.05   c. 0.10   d. 0.03

A population data set with a normal distribution has a mean u = 4 and a standard deviation o = 1.1. Find the approximate proportion of observations in the data set that lie below 5.1? O 0.84 0.17 O 0.34 0.68

The data given below are the weights for a sample of babies. Assume the population of birth weights is normally distributed with a mean of μ= 7.10   DATA: 6.88 6.00 8.19 7.44 7.06 5.06 8.38 7.44 8.31 6.38 What is the mean weight in our sample? What is the standard deviation of our sample? What is the z-score for the heaviest baby in the sample? Give both the X-value and the z-score. What is the z-score for the lightest baby in the sample? Give both the X-value and the z-score. Assuming the distribution of birth weights is normally distributed, what percent of the babies in this distribution weigh more than our heaviest baby?

For a population with mean 90 and standard deviation 10  A. find the percentile rank for a score of 95 B. Find the cutoff score (for the population with mean 90, not the z score) for top 2% C. Find the cutoff score (for the population with mean 90, not the z score) for the lowest 20 %